模拟计算压力对高岭石结构与力学性能的影响  

Simulation on Structures and Mechanical Properties of Kaoline at Different Hydrostatic Pressures

作　　者：王鹏 林雪玲 潘凤春 林龙[2] 王旭明 WANG Peng;LIN Xueling;PAN Fengchun;LIN Long;WANG Xuming(School of Physics and Electronic-Electrical Engineering,Ningxia University,Yinchuan 750021,Ningxia,China;School of Materials Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,Henan,China)

机构地区：[1]宁夏大学物理与电子电气工程学院,宁夏银川750021 [2]河南理工大学材料科学与工程学院,河南焦作454000

出　　处：《硅酸盐学报》2018年第12期1788-1794,共7页Journal of The Chinese Ceramic Society

基　　金：宁夏自然科学基金(NZ17039);国家自然科学基金(11764032,11762019,11662017);河南省自然科学基金(182300410288);河南省科技厅科技攻关项目(182102210305)资助

摘　　要：基于密度泛函理论的第一性原理方法研究了不同静水压力下高岭石的电子结构和力学性能。结果表明:高岭石的禁带宽度随着压力的增加逐步增大,其原因在于压力下体系的导带底向高能区移动;压力下高岭石片层之间的距离变小以及Si-O键和Al-O键键长变短导致了高岭石超晶胞的体积减小,同时高岭石晶体由三斜晶系向单斜晶系转变,发生了塑性形变;高岭石晶体的刚性和抵御塑性变形的能力随着压力的增加而增大,在0.6 GPa时体系的Poisson比最小且Al-O键键长达到了最小,表明此压力下高岭石晶体的横向变形最小,结构最为稳定,0.6 GPa压力下高岭石独特的力学性能主要与Al-O键的键长有关。The electronic structures and mechanical properties of Kaoline at different hydrostatic pressures were simulated by the first-principles calculation based on the density functional theory. The simulated results indicate that the band-gap of Kaoline increases with the increase of pressure because the bottom of conduction band shifts up at a pressure. The decreased distance between Kaoline lamellas and the shortened bond lengths of Si-O and Al-O both result in the reductive volume of the Kaoline supercell. Also, the crystal structure translates from triclinic system to monoclinic one, leading to the plastic deformation. The rigidity and ability to resist the plastic deformation increase as the pressure increases. The Poisson ratio and the Al-O length of the system become minimum at a pressure of 0.6 GPa, indicating the minimum transverse deformation and the most stable structure. The unique mechanical properties of Kaoline at such a pressure(i.e., 0.6 GPa) are mainly related to the Al-O bond length.

关 键 词：第一性原理 静水压力 高岭石 电子结构 力学性能 

分 类 号：O472[理学—半导体物理]